/Engine/Source/Developer/CollectionManager/Public/ICollectionManager.h
Creates a unique collection name for the given type taking the form BaseName+(unique number)
void CreateUniqueCollectionName ( const [FName](API\Runtime\Core\UObject\FName) & BaseName, [ECollectionShareType::Type](API\Developer\CollectionManager\ECollectionShareType\Type) ShareType, [FName](API\Runtime\Core\UObject\FName) & OutCollectionName ) const